In your case this will be difficult to fix. Clicking hard drive is usually the arm of the drive moving back a forth and hitting the outer wall of it's housing. You have a few choices, chances are they probably wont work (sorry) but give them a try anyway. Freeze the hard drive overnight, if the hard drive magically works again be sure to have a backup drive with you to transfer the DATA as the drive typically won't work for more than a short period of time. And the dumber options, use the hitting method... give the drive a light hit. Or you can use another method which I don't reccomend, drop the drive on the floor from about 4 inches off the ground. Other than that, find a company who fixes drives. Obviously you want the data restored and this option will probably prove to be the best. Other than that, sounds like your drives dead. I recently had the same problem.
Large maxtor drives aren't very solid... if you wan't a small drive they're great, but for the larger sizes I would go with Seagate.